Pyridylalkyl dicyandiamides and guanylureas



United States Patent 3,074,955 PYRIDYLALKYL DICYANDIAMIDES AND GUANYLUREAS Seymour L. Shapiro, Hastings-on-Hudson, and Louis Freedman, Bronxville, N.Y., assignors to US. Vitamin 8: Pharmaceutical Corporation, New York, N.Y., a cor- I poration of Delaware No Drawing. Filed Nov. 30, 1960, Ser.

6 Claims. (Cl. 260-295) amides, I), and carbamido (to give the substituted guanylureas, II)

The compounds of this invention by virtue of their pyridine ring system can readily form' salts with the non toxic miner-al acids. In addition, the guanylureas have another basic site and can be obtained as their monoor di-acid salts.

The compounds are conveniently prepared by reaction in refluxing butanol of the appropriately substituted was treated under cooling and stirring with 42 ml. of 12.

the product usually crystallized as the dihydrochl-oride of the substituted guanylurea (II).

In instances where the ldihydrochloride does not precipita-te, the product is conveniently isolated by adjusting the pH of the reaction mixture to approximately 5-6 and adding sodium nitrate which precipitates theguanylureas II,

- as the nitrate.

Equationstypifying these reactions are shown:

Equation 2 H 01 I II.2HC1

The process of compounds of this invention will be more clearly understood from a consideration of the following examples which are given for the purposes of illustration only and are not to be considered as limiting the scope of the invention in any way.

EXAMPLE 1 General procedure for preparation of the pyridylalkyl V dicyandiamides.A solution of 0.5 mole of the appropriate picolyl or pyridylethyl amine in 500 ml. of n-butanol N hydrochloric acid, followed by the addition of 55.0 g. (0.5 mole) of sodium dicyananiide. The white suspension Was heated under reflux for 6 hours with stirring.

The hot solution was filtered to separate the formed sodium chloride and after removal of the butanol, the residue of product- Was recrystallized. 'Typical of the syntheses, reflecting this invention, are the compounds listed in Table I.

' Compounds 10 and 11, which are not a part of this I invention, have been prepared to demonstrate the selective-and distinct properties of the compounds of this in- R R NH picolyl or pyridylethyl amine hydrochloride with vention.

' TABLE I I Picolyl and Pyridylethyl Dicyandiamides i" t R I IICNON Analysis, percent Yield, No. R R M.p., 0. percent Formula Carbon Hydrogen Nitrogen Calcd. Found Calcd. Found Calcd. Found H 142-145 b 48 54. 8 54. 1 5. 2 5. 1 40. 0 40. 7 H 147-150 57 54. 8 54. 6 5. 2 5. 4 40. 0 39.8 H 78- 81 31 49. 7 49. 9 5. 7 5. 7 36. 3 35. 7 CH: 150-152 39 57.1 57. l 5. 9 5. 7 37.0 37. 1 CH 158-160 54 57. 1 57. 2 5.9 6.0 37. 0 37. 1 .H 143-146 67 57.1 57.2 5. 9 6.0 37.0 37. 3 H 194-195 36 57. 1 57.2 5. 9 6.0 37.0 37. 3 CH3 165-168 b 66 59.1 58.9, .05 6. 7 CH3 202-204 b 39 CmHrsNs 59. 1 58. 8 6. 5 6. 3

4-pyridyl H 111-114 C H1N5 L 43.6 44.3 (CH3)1N(CH)3 CH3 119-121 36 O H1 N 52.4 52. 3 9. 4 9. 4 38. 2 38. 4

N e Rec rystallizing solvent is isopropyl alcohol-hexane unless otherwise shown.

b Recrystallizing solvent is'acetonitrile. Y 5 Isolated, and analyses shown as monohydrate. d Recrystallizlng solvent is ethanol-ether.

EXAMPLE 2 sodium dicyanarnide, to give upon work-up, the required dicyandiamide (I). Other solvents such as propanol, or aqueous butanol may be substituted.

The dicyandiamide (I), in turn, is readily hydrolyzed upon treatment with alcoholic solutions of 12 N hydrochloric acid. The preferred alcohol for this hydrolysis is isopropyl alcohol although other lower alcohols are equally applicable. After an appropriate reflux period,

General procedure for the preparation of the picolyl and pyridylethyl guanylureas-A suspension of 0.025 mole of the dicyandiamides described in Table I in a mixture of 12 ml. of isopropyl alcohol and 6 ml. of 12 N hydrochloric acid was heated under reflux, with stirring, over a period of 2-3 hours. When cool, the formed product as the dihydrochloride, separated and was filtered and recrystallized. In those instances wherein the product did of hydrogen and methyl, and Z is selected from the group not crystallize, the reaction mixture was diluted with consisting of cyano and carbamido; and the nontoxic Water (70 ml.) and neutralized (to methyl red) with N mineral acid salts thereof. sodium hydroxide and 5.3 g. of sodium nitrate added. 2. The compound The precipitated mo-nom'trate salt of the product was sep- 5 H H arated and recrystallized. The salts of the product, on N C N suspension in water or a lower alcohol, and treatment with H T an equivalent quantity of base afforded the free base of NH the guanylurea. Typical of the compounds prepared, are those described in Table II.

TABLE II Analysis, percent No. R; R; HX M. p., O. Yield, Formula Carbon Hydrogen Nitrogen Calcd. Found Calcd. Found Calcd. Found 2picolyl H 193-194 CMHHNBOS 36.9 36.8 2.6 2.6 23.7 24.1 3-pico1yl H 175-177 27 GBHHNQOJ 37.5 37.7 4.7 4.3 32.5 33.0 2-py'ridylethyl. H 198-200 18%..." QHiiClzNsO ass 39.2 5.4 5.4 25.0 24.7 4-pyridylethyl H 220-221 33 CQHuClnNsO 38.6 38.5 5.4 5.2 25.0 24.5 2-pyridylethyl CH; 183-184 35 10II!70l2N60 40.8 40.0 5.8 6.0 23.8 23.5 4-pyridylethyl CH3 189-191 32 OroHwNaO; 42.3 43.1 5.7 5.7 29.6 29.5

B Reerystallizing solvent: aa=80% methanol; al0=Water; ac=Methyl cellosolve-acetonitrlle; ad=Methyl cellosolve; ae=Methanol-benzene; af= Ethanol-hexane.

b HPic=Picric acid.

The compounds of this invention have important phar- 3. The compound macological properties and, in particular, the dicyandi- CH3 amides (I) are relatively nontoxic compounds (LD 750-1,000 mg./kg.) which are particularly active as po- I tentiators of central nervous system depressant drugs.

By contrast, the (4-pyridyl)-dicyandiamide is toxic at 20 mg./kg. s.c. and shows no distinctive pharmacological properties.

In addition, the N-methyl-dimethylarnino propyl di- 45 cyandiamide, also prepared for purposes of comparison, CHzCHz-N(I'|JNCE 4. The compound while having substantially little toxicity (LD 1,000 NH mg./kg.) is without import-ant pharmacological effect.

The pyridylalkyl guanylureas manifest their eifects, particularly in lowering as well as raising blood pressure, as 5 T e compound the groups are varied. Additionally, they potentiate as H 11 well as inhibit adrenalin significantly, as the groups are CH l l NH varied. I a 2 It is to be understood that it is intended to cover all changes and modifications of the examples herein chosen for the purposes of illustration which do not constitute The compound departure from the spirit and scope of the invention.

We claim: E H

1 Th compound OHaOHr-N-fi-N-(fi-NH:

NH References Cited in the file of this patent UNITED STATES PATENTS wherein R is selected from the group consisting of picolyl, 2,455,894 Lechcr et a1 Dec. 7, 1948 and pyridylethyl, R is selected from the group consisting 2,455,896 gy fi 8 

1. THE COMPOUND
 5. THE COMPOUND 